Means for producing magnifications of minute movements



A 1. e. STEWART. MEANS FOR PRODUCING MAGNIFICATIONS OFMINUTE MOVEMENTS.

' APPLICATION FILED APR.2, 1920. 1,392,239.

Patented Sept: 27,1921.

UNITED STATES PATENT OFFICE.

JAMES GIBB STEWART, OF DUNDEE, SCOTLAND.

MEANS FOR PRODUCING MAGNIFICATIONS 0F MINUTE MOVEMENTS.

Application filed April, 2,

To all "whom it may concern:

Be it'known that I, JAMns GIBB STEWART, a subject of the King of Great Britain and Ireland, residing at 31 Isles Lane, Dundee, Scotland, have invented new and useful Improvements in or Connected with Means for Producing Magnifications of Minute Move-. ments, of which the following is a specification.

This invention, which relates to means for producing magnifications of minute movements particularly applicable for use 1n the construction of gaging, indicating, recording and like instruments, comprises the provision of two flexible members, each narrow in comparison with its length and thin according to the flexibility required, which is mainly angular flexibility about a longitudinal axis. These members are arranged opposite one another with their longitudinal axes contained in a plane normal or approximately so to their surfaces. At a position, say, midway between their ends, the members are rigidly connected together, and

the ends of one member are fixed to a stationary support and those of the other to a movable frame, the arrangement being such that upon applying force to the movable frame in a direction at right angles to the plane in which the longitudinal axes of the members are normally contained, angular movement is produced at the position where the members are connected about or approx1- mately about a longitudinal axis contained in the aforesaid plane parallel, coincident or approximately so with the longitudinal. axis of the member fixed to the stationary support. The angular movement thus produced, which is proportional to the movement imparted to the movable frame, may

Specification of Letters Patent. -Pa1 ented S t 27 1921 1920. Serial No. 370,840.

flexible members composed of spring steel, C a stationary support to which the ends of the member A are fixed and D a movable frame to which the ends of the member B are fixed. At a position midway between their ends the members A, B, are fixed together by a connector, in this case comprising an intervening distance piece E associated with two outside pieces E E secured together by screws E By these means the movable frame D derives support partly from the stationary support C, supplementary support and guidance being pro vided, for example, in the case of Fig. 1 by straps F, F, fixed at onelend one to each end of an extension D of the frame D and at the other end to stationary standards G which form a lateral guide for the movable frame. The straps F, F, which may be composed of spring steel or other suitable material, op-

erate to guide the frame D when moved in.

a direction at right angles or approximately so to the plane containing the longitudinal axes of the members when in their normal condition, and the length of the straps F may be such that the support C and frame D are separatedby a distance which is equal: to or greater or less than that at which normal support by the connected members A,

B alone would produce, with the result that when greater orless than the normal the members are deformed each from its original, in this case straight, condition. The adjacentends of the members A, B may thus be held at a greater or less distance apart than the adjacent portions at the position of connection.

A further example of means for supple-,

menting the support and for so guiding the movable frame D thatit is capable of being movedonly in a direction at right angles or approximately so to the plane containing the longitudinal axes of the flexible members A, B when in their normal condition, is embodied in the construction illustrated at Fig. 2, which construction corresponds in other respects with Fig. 1. In this case the lateral guide is formed by the extension D of the movable frame D being arranged to extend through and slide in a fixed guide G The movement to be measured may, for example, be determined by applying the .movement at the position H, see Figs. 1 and with this place, the elongation ofwhich under heating effects 1s desired to be measured. The elongatlon produced Wlll thus operate to move the frame D and thereby produce an" angular movement of the connector E, the extent of which may be indicated directly by an index finger K extending from the connector E associated with a scale L over which the outer end of the fingerrmoves.

A convenient method of multiplying the scale indication is shown at Fig. 3, in which. case the part E of the connector is furnished with an arm E having at its outer end a toothed segment N which meshes with a toothed wheel P fixed upon a spindle P on which is fixed an index finger K arranged to move over a scale L graduated as required;

Other methods of supplementing the support and guiding the movable frame D may be adopted, and although flexible members which in their natural condition are flat are particularly suitable, that condition is not essential. Further, the conditions at the position where the two members are connected, in so far as the extent of angular movement produced is concerned, depend upon the dis tance which at this position the'longitudinal axes of the two members are apart,

I claim: r

1. An instrument consisting of two flexible members each narrow in comparison with its length andthin according to the flexibility required, arranged opposite one another with their longitudinal axes con-- tained in a plane normal or approximately so to their surfaces, a connector by which the two flexible members are rigidly connected together at a position between their ends, a stationary support to which the ends of one member are fixed, amovable frame to which the ends of the other member are fixed, a lateral guide for the movable frame, and means to which the angular movements of the connector are imparted, for the purposes set forth. i

2. An instrument consisting of two flexible members each narrow in comparison with its length and thin according to the flexibility required, arranged opposite one another with their longitudinal axes contained in a plane normal or approximately so to their surfaces, a connector by which the two' flexible members are rigidly connected together at a position between their ends, a stationary support to which the ends of one member are fixed, a movable frame to which the ends of the other member are fixed, an extension from the movable frame, stationary standards, flexible straps fixed at one end one to each end of the extension frointhe'movable frame and at the other end to the stationary standards, and means to which the angular movements of the connector are imparted, for the purposes set forth.

An instrument consisting of twoflexi ble members each narrow in comparison with its length and thin according to the flexibility required, arranged opposite one another with their longitudinal axes conained in, a plane normal or approximately so to. their surfaces, a connector by which the two flexible members are rigidly con-,

nected together at a position between their ends, a stationary support to which the ends of one member are fixed, a movable frame to which the ends of the other member are fixed, a lateral guide for the movable frame, and an index finger to which the angular movements of the connector are imparted, for the purposes set forth. I

l. An instrument consisting of two flexible members each narrow in comparison with its length and thin according to the flexibility required, arranged opposite one another with theirlongitudiual axescontained in a plane normal or approximately so to their surfaces, a connector by which the two flexible members are rigidly connected together at'a position between their ends, a stationary support to which the ends.

from'the connector, for the purposes set forth.

, JAMES e BB STEWART. 

